FIX: topic_tracking_state when mute_all_categories_by_default is enabled

app/models/topic_tracking_state.rb

@@ -306,9 +306,10 @@ class TopicTrackingState
           #{tags_filter}
           topics.deleted_at IS NULL AND
           #{category_filter}
-          (category_users.notification_level IS NULL OR
+          NOT (
-          last_read_post_number IS NOT NULL OR
+            last_read_post_number IS NULL AND
-          category_users.notification_level <> #{CategoryUser.notification_levels[:muted]})
+            COALESCE(category_users.notification_level, #{CategoryUser.default_notification_level}) = #{CategoryUser.notification_levels[:muted]}
+          )
 SQL
 
     if opts[:topic_id]

lib/topic_query.rb

@@ -857,8 +857,6 @@ class TopicQuery
     category_id = get_category_id(opts[:exclude]) if opts
 
     if user
-      default_notification_level = SiteSetting.mute_all_categories_by_default ? CategoryUser.notification_levels[:muted] : CategoryUser.notification_levels[:regular]
-
       list = list
         .references("cu")
         .joins("LEFT JOIN category_users ON category_users.category_id = topics.category_id AND category_users.user_id = #{user.id}")
@@ -866,7 +864,7 @@ class TopicQuery
                 OR COALESCE(category_users.notification_level, :default) <> :muted
                 OR tu.notification_level > :regular",
                 category_id: category_id || -1,
-                default: default_notification_level,
+                default: CategoryUser.default_notification_level,
                 muted: CategoryUser.notification_levels[:muted],
                 regular: TopicUser.notification_levels[:regular])
     elsif SiteSetting.mute_all_categories_by_default

spec/models/topic_tracking_state_spec.rb

@@ -366,6 +366,26 @@ describe TopicTrackingState do
     expect(report.length).to eq(1)
   end
 
+  it "works when categories are default muted" do
+    SiteSetting.mute_all_categories_by_default = true
+
+    user = Fabricate(:user)
+    post
+
+    report = TopicTrackingState.report(user)
+    expect(report.length).to eq(0)
+
+    CategoryUser.create!(user_id: user.id,
+                         notification_level: CategoryUser.notification_levels[:regular],
+                         category_id: post.topic.category_id
+                         )
+
+    create_post(topic_id: post.topic_id)
+
+    report = TopicTrackingState.report(user)
+    expect(report.length).to eq(1)
+  end
+
   context 'muted tags' do
     it "remove_muted_tags_from_latest is set to always" do
       SiteSetting.remove_muted_tags_from_latest = 'always'